diff --git a/libs/backends/portaudio/winmmemidi_input_device.cc b/libs/backends/portaudio/winmmemidi_input_device.cc
index 929f099834..9923a108dc 100644
--- a/libs/backends/portaudio/winmmemidi_input_device.cc
+++ b/libs/backends/portaudio/winmmemidi_input_device.cc
@@ -21,6 +21,7 @@
 #include "winmmemidi_input_device.h"
 
 #include <stdexcept>
+#include <cassert>
 #include <cmath>
 
 #include "pbd/compose.h"
diff --git a/libs/backends/portaudio/winmmemidi_input_device.h b/libs/backends/portaudio/winmmemidi_input_device.h
index 3e7e1b728c..4d8a2689d1 100644
--- a/libs/backends/portaudio/winmmemidi_input_device.h
+++ b/libs/backends/portaudio/winmmemidi_input_device.h
@@ -26,6 +26,7 @@
 #include <stdint.h>
 
 #include <string>
+#include <memory>
 
 #include <pbd/ringbuffer.h>